\n\tclc; clear; close;
\nlx=1680; ly=140;
\nlyp=0.005;%m
\nLr=lyp\/ly;
\ncs=1\/3^0.5; c_squ=cs^2;
\nt1=4\/9; t2=1\/9; t3=1\/36;
\nRe=400;
\nUin=0.02; D=fix(0.022\/Lr);
\nnu=D*Uin\/Re;
\ntau=3*nu+0.5;
\nomega=1\/tau;
\nt= [1\/9,1\/36,1\/9,1\/36,1\/9,1\/36,1\/9,1\/36,4\/9];
\nex=[1, 1, 0, -1, -1, -1, 0, 1, 0];
\ney=[0, 1, 1, 1, 0, -1, -1, -1, 0];
\noppo=[5,6,7,8,1,2,3,4,9];
\nrho=ones(ly,lx);
\nUX=zeros(ly,lx);
\nUX=Uin;
\nUY=zeros(ly,lx);
\nF=zeros(ly,lx,9);
\nFEQ=FEQf(UX,UY,rho,t1,t2,t3,c_squ);
\nF=FEQ; Fb=F;
\n[y,x]=meshgrid(1:ly,1:lx); %\u751f\u6210\u5e8f\u53f7\u7f51\u683c
\nbound =[((x'-[lx\/4]).^2 + (y'-[D\/2]+510).^2 )<=(D\/2)^2]+...
\n [y'==1]+[y'==ly];
\nobs=find(bound); %\u627e\u5230\u58c1\u9762\u7f51\u683c\u7684\u5168\u5c40\u4f4d\u7f6e
\nm=length(obs);
\nb2b=zeros(9*m,1); bid=zeros(9*m,1);
\nfor i=0:8
\n bid(i*m+1:(i+1)*m)=(oppo(i+1)-1)*lx*ly+obs;
\n b2b(i*m+1:(i+1)*m)=i*lx*ly+obs;
\nend<\/p>\n

for i=1:80000
\nF=stream(F,ly,lx);
\nrho = sum(F,3); <\/span> %\u8ba1\u7b97\u5bc6\u5ea6
\nUX=(sum(F(:,:,[1 2 8]),3)-sum(F(:,:,[4 5 6]),3)).\/rho; %\u8ba1\u7b97x\u901f\u5ea6
\nUY=(sum(F(:,:,[2 3 4]),3)-sum(F(:,:,[6 7 8]),3)).\/rho; %\u8ba1\u7b97y\u901f\u5ea6
\nUX(obs)=0; UY(obs)=0;
\nUX(2:ly-1,1)=Uin*(2:ly-1)\/(ly-1).*(1-(2:ly-1)\/(ly-1))*4; UY(2:ly-1,1)=0;
\nrho (2:ly-1,1)=rho (2:ly-1,2); %\u5bc6\u5ea6\u91c7\u7528\u5916\u63a8
\nUX(2:ly-1,lx)= UX(2:ly-1,lx-1); %\u53f3\u7aef\u51fa\u53e3\uff0c\u901f\u5ea6\u91c7\u7528\u5916\u63a8
\nUY(2:ly-1,lx)= UY(2:ly-1,lx-1);
\nrho (2:ly-1,lx)=1; %\u5bc6\u5ea6\u6307\u5b9a
\nP=cs^2*rho;
\nFEQ=FEQf(UX,UY,rho,t1,t2,t3,c_squ);
\nBOUNCEBACK=F(b2b); %\u83b7\u5f97\u53cd\u5f39\u91cf
\nF=omega*FEQ+(1-omega)*F; %\u78b0\u649e
\nF(bid)=BOUNCEBACK; %\u5c06\u53cd\u5f39\u91cf\u8d4b\u4e88\u76f8\u5e94\u4f4d\u7f6e
\nF(2:ly-1,1,:)=FEQ(2:ly-1,1,:)+((F(2:ly-1,2,:)-FEQ(2:ly-1,2,:))); %\u5de6\u8fb9\u5165\u53e3
\nF(2:ly-1,lx,:)=FEQ(2:ly-1,lx,:)+((F(2:ly-1,lx-1,:)-FEQ(2:ly-1,lx-1,:))); %\u53f3\u8fb9\u51fa\u53e3
\n%\u7ed3\u679c\u663e\u793a
\nOutputRes;
\nend \n<\/p>\n

\n\t%%\u5e73\u8861\u6001\u5206\u5e03\u51fd\u6570%%%%%%%%%%%%%%%%%%%%%%%<\/span>\n<\/p>\n

\n\tfunction FEQ=FEQf(UX,UY,rho,t1,t2,t3,c_squ)
\n U_SQU=UX.^2+UY.^2; U_C2=UX+UY;
\n U_C4=-UX+UY; U_C6=-U_C2;
\n U_C8=-U_C4;
\n FEQ(:,:,9)=t1*rho.*(1-U_SQU\/(2*c_squ));
\n FEQ(:,:,1)=t2*rho.*(1+UX\/c_squ+0.5*(UX\/c_squ).^2-U_SQU\/(2*c_squ));
\n FEQ(:,:,3)=t2*rho.*(1+UY\/c_squ+0.5*(UY\/c_squ).^2-U_SQU\/(2*c_squ));
\n FEQ(:,:,5)=t2*rho.*(1-UX\/c_squ+0.5*(UX\/c_squ).^2-U_SQU\/(2*c_squ));
\n FEQ(:,:,7)=t2*rho.*(1-UY\/c_squ+0.5*(UY\/c_squ).^2-U_SQU\/(2*c_squ));
\n FEQ(:,:,2)=t3*rho.*(1+U_C2\/c_squ+0.5*(U_C2\/c_squ).^2-U_SQU\/(2*c_squ));
\n FEQ(:,:,4)=t3*rho.*(1+U_C4\/c_squ+0.5*(U_C4\/c_squ).^2-U_SQU\/(2*c_squ));
\n FEQ(:,:,6)=t3*rho.*(1+U_C6\/c_squ+0.5*(U_C6\/c_squ).^2-U_SQU\/(2*c_squ));
\n FEQ(:,:,8)=t3*rho.*(1+U_C8\/c_squ+0.5*(U_C8\/c_squ).^2-U_SQU\/(2*c_squ));\n<\/p>\n

\n\t\n<\/div>\n

%%\u8fc1\u79fb%%%%%%%%%%%%%%%%%%%%%%%<\/span><\/span><\/span> <\/p>\n

\n\t\n<\/p>\n

\n\tfunction F=stream(F,ly,lx)
\nF(:,:,1)=F(:,[lx 1:lx-1],1);
\nF(:,:,2)=F([ly 1:ly-1], [lx 1:lx-1],2);
\nF(:,:,3)=F([ly 1:ly-1],:,3);
\nF(:,:,4)=F( [ly 1:ly-1], [2:lx 1],4);
\nF(:,:,5)=F(:,[2:lx 1],5);
\nF(:,:,6)=F([2:ly 1], [2:lx 1],6);
\nF(:,:,7)=F([2:ly 1],:,7);
\nF(:,:,8)=F([2:ly 1],[lx 1:lx-1],8);\n<\/p>\n

\n\t\n<\/p>\n

\n\t%%\u7ed3\u679c\u663e\u793a%%%%%%%%%%%%%%%%%%%%%%%<\/span>\n<\/p>\n

\n\t if mod(i,300)==0
\n clc ; clf; i
\n U = sqrt(UX.^2+UY.^2);
\n hold on
\n DUX=diff(UX);
\n DUY=diff(UY);
\n Vor=DUY(1:ly-1,1:lx-1)-DUX(1:ly-1,1:lx-1);
\n contour(Vor,100);
\n imagesc(0,300,U,[0,1.5*Uin])
\n XL=(2:2:ly-1)+150;
\n streamline(x',y'+150,UX,UY,ones(1,length(XL)),XL,1)
\n colormap('jet');axis equal; drawnow;
\n hold off
\n end<\/p>\n

<\/span>\n<\/p>\n

\n\t<\/p>\n","protected":false},"excerpt":{"rendered":"